Cocaine dependence continues to be a significant public health concern. Data from the National Survey on Drug Use and Health indicate that the number of Americans who had used cocaine in the past month has remained relatively stable since 2002 and cocaine remains the most frequently mentioned drug in emergency-room admissions according to the Drug Abuse Warning Network. Because of the public-health concerns and costs associated with its abuse, identifying a pharmacotherapy for the treatment of cocaine dependence is a priority for the National Institute on Drug Abuse (NIDA). Despite intense research efforts, a widely accepted medication for cocaine dependence has not yet been identified. A number of non-pharmacological treatments for cocaine dependence have also been examined. Specifically, behavioral treatments for cocaine dependence seek to reinforce non- drug related behaviors. For example, contingency management uses monetary incentives to decrease cocaine use and is associated with high rates of prolonged cocaine abstinence. Given the effectiveness, but also high relative cost, of behavioral treatments for cocaine dependence, some have theorized that pharmacotherapies may be able to enhance the effectiveness of behavioral therapies and decrease costs associated with delivery of these therapies. Indeed, pharmacotherapies (i.e., desipramine and bupropion) have been shown to enhance the effectiveness of behavioral therapies for cocaine dependence. The purpose of the experiments proposed in this application is to "reverse engineer" a human laboratory model of combined pharmacological and behavioral treatments for cocaine dependence using an already existing and validated model of contingency management, the cocaine versus money choice paradigm. The research proposed in this application has two specific aims. The first specific aim is to adapt a model of the cocaine versus money choice paradigm that is sensitive to pharmacological pretreatment (Higgins et al., 1996) and determine optimal parameters (i.e., cocaine dose, monetary values). In Experiment 1, eight non-treatment seeking cocaine-dependent subjects will choose between a range of doses of intranasal cocaine and monetary values. These data will be used to guide which cocaine dose and monetary values will be used in Experiment 2. The second specific aim is to validate the sensitivity of the cocaine versus money choice paradigm as a model of combined pharmacological and behavioral treatment. In Experiment 2, eight non-treatment seeking cocaine-dependent subjects will choose between a range of doses of intranasal cocaine and monetary values following maintenance for seven days on placebo or 300 mg bupropion. The research proposed in this application will serve to develop an efficient and valid human laboratory screen of medications for cocaine dependence. Project Narrative The research proposed in this application seeks to develop a model of combined behavioral and pharmacological treatment for cocaine dependence. With this model, we hope to more efficiently screen medications that might enhance the efficacy of contingency management, a behavioral treatment that is successful in managing cocaine dependence.